Studies of pulmonary platelet trapping and pulmonary edema as a consequence of central nervous system trauma, peripheral trauma, and endotoxin shock will continue. The effects of the opiate inhibitor, Naloxone, in preventing the sequelae of trauma will be studied, as will the effects of alpha and beta blocking agents and platelet inhibiting drugs such as dipyridamole and aspirin. We will study the effect of Naloxone on platelet adhesion to major endothelial surfaces, and the effects of this drug on in vitro aggregation. It has been reported that increased intracranial pressure is associated with augmented lymph flow. An attempt will be made to measure lymph flow from the lung and to determine if denervation affects this increase in lymph flow. The effects of Naloxone on lymph flow will also be determined. Cast models of the vascular system of the dog's hind limb and of the lung will be made during normotensive and hypotensive states to see whether differences in the vascular tree can be defined anatomically by this method.